Pediatric mastocytosis

[Mastocytosis in children]

Mastocytosis in children is a rare disease characterized by an abnormal accumulation of tissue mast cells. Mastocytosis in children presents with typical skin alterations that are classified as maculopapular cutaneous mastocytosis, diffuse cutaneous mastocytosis, or mastocytoma. Some patients also develop mast cell mediator symptoms, such as pruritus, flush, and anaphylaxis. In many children, the disease is characterized by a benign and usually self-limiting course; systemic mastocytosis with extracutaneous involvement and a chronic or progressive course is found only rarely. Therapeutically, H1 antihistamines are primarily used on an as-needed basis or as continuous treatment, depending on the severity. Children, parents and caregivers should be thoroughly educated about the clinical picture and possible trigger factors of mast cell mediator release. For children with extensive skin alterations and severe symptoms, the prescription of an epinephrine auto-injector is recommended for emergency treatment.

Mastocytosis in children: a single-center long-term follow-up study

BACKGROUND

Mastocytosis is a heterogeneous group of rare disorders characterized by the accumulation of clonal mast cells in organs such as the skin and bone marrow. The diagnosis of cutaneous mastocytosis (CM) is based on clinical findings, positive Darier's sign, and histopathology, if necessary.

METHODS

Medical records of 86 children with CM diagnosed during a 35-year long period were reviewed. Most patients (93%) developed CM during the first year of life (median age 3 months). Clinical features at presentation and during the follow-up period were analyzed. Baseline serum tryptase level was measured in 28 patients.

RESULTS

A total of 85% of patients had maculopapular cutaneous mastocytosis/urticaria pigmentosa (MPCM/UP), 9% had mastocytoma, and 6% had diffuse cutaneous mastocytosis (DCM). Boy to girl ratio was 1.1:1. Fifty-four of 86 patients (63%) were followed from 2 to 37 years (median 13 years). Complete resolution was registered in 14% of mastocytoma cases, 14% of MCPM/UP, and in 25% of DCM patients. After the age of 18, skin lesion persisted in 14% mastocytoma, 7% MCPM/UP, and 25% children with DCM. Atopic dermatitis was diagnosed in 9.6% of patients with MPCM/UP. Three of 28 patients had elevated serum tryptase. Prognosis in all patients was good, and there were no signs of progression to systemic mastocytosis (SM).

CONCLUSION

To the best of our knowledge, our results represent the longest single-center follow-up study of childhood-onset CM. We found no complications of massive mast cell degranulation or progression to SM.

Modulation of dermal equivalent of hypothalamus-pituitary-adrenal axis in mastocytosis

Introduction

Mastocytosis is a rare disease characterized by abnormal growth and accumulation of tissue mast cells (MC) in one or more organ systems and is classified as being either cutaneous mastocytosis (CM) or systemic mastocytosis (SM). In the pioneer studies of Slominski's group, a fully functional hypothalamic-pituitary-adrenal axis equivalent has been discovered in various tissues, including skin.

Aim

In the present study we investigated potential involvement of hypothalamus-pituitary-adrenal (HPA) cutaneous equivalent in ongoing mastocytosis.

Material and methods

The expression of HPA elements: CRH, UCN1, UCN2, UCN3, CRHR1, POMC, MC1R, MC2R and NR3C1 was assessed for their mRNA level in skin biopsies of adult patients with mastocytosis and healthy donors (n = 16 and 19, respectively), while CRH, UCN1, CRHR1, ACTH and MC1R were selected for immunostaining assay (n = 13 and 7, respectively). The expression of CRH receptor 1 (CRHR1) isomers was investigated by RT-PCR. The ELISA was used for detection of cortisol, CRH, UCN and ACTH in the serum.

Results

The decrease in the expression of HPA element of skin equivalent was observed on both mRNA and protein levels, however quantification of immunohistochemical data was impeded due to melanin in epidermis. Furthermore, we observed infiltration of dermis with HPA elements overexpressing mononuclear cells, which is in the agreement with an in vitro study showing a high expression of HPA elements by mast cells.

Conclusions

Taken together, it was confirmed that the expression elements of HPA was modulated in mastocytosis, thus the potential involvement of general and local stress responses in its pathogenesis should be postulated and further investigated.

Systemic Mastocytosis: Molecular Landscape and Implications for Treatment

Over the past decade, we have witnessed significant advances in the molecular characterization of systemic mastocytosis (SM). This has provided important information for a better understanding of the pathogenesis of the disease but has also practically impacted the way we diagnose and manage it. Advances in molecular testing have run in parallel with advances in therapeutic targeting of constitutive active KIT, the major driver of the disease. Therefore, assessing the molecular landscape in each SM patient is essential for diagnosis, prognosis, treatment, and therapeutic efficacy monitoring. This is facilitated by the routine availability of novel technologies like digital PCR and NGS. This review aims to summarize the pathogenesis of the disease, discuss the value of molecular diagnostic testing and how it should be performed, and provide an overview of present and future therapeutic concepts based on fine molecular characterization of SM patients.

Proceedings from the Inaugural American Initiative in Mast Cell Diseases (AIM) Investigator Conference

The American Initiative in Mast Cell Diseases (AIM) held its inaugural investigator conference at Stanford University School of Medicine in May 2019. The overarching goal of this meeting was to establish a Pan-American organization of physicians and scientists with multidisciplinary expertise in mast cell disease. To serve this unmet need, AIM envisions a network where basic, translational, and clinical researchers could establish collaborations with both academia and biopharma to support the development of new diagnostic methods, enhanced understanding of the biology of mast cells in human health and disease, and the testing of novel therapies. In these AIM proceedings, we highlight selected topics relevant to mast cell biology and provide updates regarding the recently described hereditary alpha-tryptasemia. In addition, we discuss the evaluation and treatment of mast cell activation (syndromes), allergy and anaphylaxis in mast cell disorders, and the clinical and biologic heterogeneity of the more indolent forms of mastocytosis. Because mast cell disorders are relatively rare, AIM hopes to achieve a coordination of scientific efforts not only in the Americas but also in Europe by collaborating with the well-established European Competence Network on Mastocytosis.

Cutaneous Mastocytosis in Childhood-Update from the Literature

Mastocytosis (M) represents a systemic pathology characterized by increased accumulation and clonal proliferation of mast cells in the skin and/or different organs. Broadly, M is classified into two categories: Cutaneous mastocytosis (CM) and systemic mastocytosis (SM). In children, CM is the most frequent form. Unfortunately, pathogenesis is still unclear. It is thought that genetic factors are involved, but further studies are necessary. As for features of CM, the lesions differ in clinical forms. The most important fact is evaluating a pediatric patient with CM. It must comprise laboratory exams (with baseline dosing of total serum tryptase), a skin biopsy (with a pathological exam and, if the diagnosis is unclear, immunohistochemical tests), and a complete clinical evaluation. It is also defining to distinguish between CM and other diseases with cutaneous involvement. As for the management of CM in children, the first intervention implies eliminating trigger factors. The available cures are oral H1 and/or H2 antihistamines, oral cromolyn sodium, oral methoxypsoralen therapy with long-wave psoralen plus ultraviolet A radiation, potent dermatocorticoid, and calcineurin inhibitors. In children, the prognosis of CM is excellent, especially if the disease's onset is in the first or second years of life.

Molecular Background, Clinical Features and Management of Pediatric Mastocytosis: Status 2021

Pediatric mastocytosis is a heterogeneous disease characterized by accumulation of mast cells in the skin and less frequently in other organs. Somatic or germline mutations in the KIT proto-oncogene are detected in most patients. Cutaneous mastocytosis is the most common form of the disease in children. In the majority of cases, skin lesions regress spontaneously around puberty. However, in few patients, mastocytosis is not a self-limiting disease, but persists into adulthood and can show signs of systemic involvement, especially when skin lesions are small-sized and monomorphic. Children with mastocytosis often suffer from mast cell mediator-related symptoms. Severe hypersensitivity reactions can also occur, mostly in patients with extensive skin lesions and blistering. In a substantial number of these cases, the triggering factor of anaphylaxis remains unidentified. Management of pediatric mastocytosis is mainly based on strict avoidance of triggers, treatment with H1 and H2 histamine receptor blockers, and equipment of patients and their families with epinephrine auto-injectors for use in severe anaphylactic reactions. Advanced systemic mastocytosis occurs occasionally. All children with mastocytosis require follow-up examinations. A bone marrow investigation is performed when advanced systemic mastocytosis is suspected and has an impact on therapy or when cutaneous disease persists into adulthood.

Mastocytosis - pathogenesis, clinical manifestation and treatment

The term mastocytosis designates a group of rare disorders characterized by typical skin lesions, frequently associated episodes of anaphylaxis, and clinical symptoms related to the release of various mediators. Dermatologists/allergists are frequently the first to establish the diagnosis. The condition is based on clonal mast cell proliferation, usually in the skin or bone marrow and only rarely in the gastrointestinal tract or other tissues. In general, mastocytosis has a good prognosis in terms of life expectancy. Rare variants - including mast cell leukemia, aggressive mastocytosis, and the exceedingly rare mast cell sarcoma - require cytoreductive therapy. In cases associated with hematological neoplasms, the prognosis depends on the underlying hematologic disorder.

Pediatric Expression of Mast Cell Activation Disorders

Mast cell activation disorders is a term proposed to cover diseases and conditions related to activation of mast cells and effects of mast cell mediators. In its broadest sense, the term encompasses a wide range of diseases from allergic asthma to rhinoconjunctivitis, urticaria, food allergy, anaphylaxis, mastocytosis, and other conditions where MC activation is contributing to the pathogenesis. This article focuses on clinical presentations, challenges, and controversies in pediatric mastocytosis and gives an overview of current knowledge and areas in need of further research.

Diffuse Cutaneous Mastocytosis in a Child - a Case Report

Mastocytosis refers to a group of diseases characterized by a clonal proliferation and accumulation of mast cells in one or more tissues/organs with different clinical presentations. In children, limited cutaneous forms of mastocytosis are rather frequent, while systemic mastocytosis is rare. The diagnosis of cutaneous mastocytosis is based on clinical findings and histopathology. We present a patient who developed skin lesions at the age of 18 months. Clinical findings, confirmed by histopathology, were consistent with diffuse cutaneous mastocytosis. The follow-up period was 7 years. The treatment included oral antihistamines in combination with mast cell stabilizers, mild topical steroids and avoidance of friction. During the follow-up period, there were no signs of systemic involvement, and the quality of life was preserved, despite the large surface of affected skin. This case report should increase the awareness and knowledge of clinicians about this rare form of cutaneous mastocytosis in the pediatric population.

Mast cell disorders: Kids are not just little people

Cutaneous mastocytosis is characterized by a pathologic increase in mast cells in the skin and may also involve extracutaneous organs. Symptoms, which are triggered by mast cell degranulation, vary depending on the burden of skin disease and the presence of extracutaneous disease. The clinical presentation, risk of systemic disease, pathogenesis, prognosis, and treatment options differ, largely depending on age at presentation. In the pediatric population, spontaneous remission is typical, generally by puberty, whereas in adults, progression is observed. Extracutaneous involvement and associated hematologic disorders seldom occur in children, as opposed to adults. It is therefore important to avoid overreliance on adult-based approaches to management of cutaneous mastocytosis in the pediatric population. We focus on differences in presentation, workup, and management of pediatric- and adult-onset cutaneous mast cell disorders.

Transient hypogammaglobulinaemia of infants in children with mastocytosis - strengthened indications for vaccinations

Mastocytosis is a disease caused by the accumulation of mast cells (MC) in the skin and/or in other tissues. Both the cutaneous form of the disease (CM) predominating in children and the systemic form (SM) typical for adults are associated with the occurrence of MC mediator-related symptoms. The release of mediators can be induced by physical stimuli and/or specific triggering factors. The routine vaccination program performed in the majority of children in infancy can be considered as an additional factor provoking exacerbation of CM. Conscious of the important role of MC in the innate immunity, we have analysed retrospective data concerning the levels of immunoglobulins, an adaptive factor, in a group of 74 infants and toddlers with CM. The values corresponding to transient hypogammaglobulinaemia of infants (THI) were found in 8 (10.81%) of cases. Classification of the antibody deficiency was done according to the working definitions for clinical diagnosis of primary immunodeficiency of the European Society of Immunodeficiencies (ESID) Registry - version May 11, 2015. Following the retrospective data, the final diagnosis of THI cannot be made due to the young age of the study group. The percentage may significantly exceed the published incidence of THI, i.e. about 0.11%. The results of our study may indicate, importantly, a higher incidence of THI in childhood-onset mastocytosis than in the general paediatric population and strengthen indications for vaccinations. In conclusion, we suggest that THI may be considered as a new aspect of paediatric mastocytosis that requires further investigation.

Current approach to cutaneous mastocytosis in childhood

Mastocytosis is a heterogeneous disorder characterized by clonal proliferation and accumulation of mast cells in one of more organs which may lead to different clinical pictures. Pathological increase and activation of mast cells in various tissues can cause different clinical pictures. Cutaneous mastocytosis limited to the skin is the most typical clinical picture observed in children and systemic mastocytosis is very rare in the pediatric age group. The diagnosis of cutaneous mastocytosis is based on clinical findings, but is often delayed due to lack of clinical awareness of the disease and lack of its consideration in the differential diagnosis. This article focuses on the current diagnosis, management and treatment of cutaneous mastocytosis in children in order to increase awareness about this issue.

Cutaneous manifestations in patients with mastocytosis: Consensus report of the European Competence Network on Mastocytosis; the American Academy of Allergy, Asthma & Immunology; and the European Academy of Allergology and Clinical Immunology

Cutaneous lesions in patients with mastocytosis are highly heterogeneous and encompass localized and disseminated forms. Although a classification and criteria for cutaneous mastocytosis (CM) have been proposed, there remains a need to better define subforms of cutaneous manifestations in patients with mastocytosis. To address this unmet need, an international task force involving experts from different organizations (including the European Competence Network on Mastocytosis; the American Academy of Allergy, Asthma & Immunology; and the European Academy of Allergology and Clinical Immunology) met several times between 2010 and 2014 to discuss the classification and criteria for diagnosis of cutaneous manifestations in patients with mastocytosis. This article provides the major outcomes of these meetings and a proposal for a revised definition and criteria. In particular, we recommend that the typical maculopapular cutaneous lesions (urticaria pigmentosa) should be subdivided into 2 variants, namely a monomorphic variant with small maculopapular lesions, which is typically seen in adult patients, and a polymorphic variant with larger lesions of variable size and shape, which is typically seen in pediatric patients. Clinical observations suggest that the monomorphic variant, if it develops in children, often persists into adulthood, whereas the polymorphic variant may resolve around puberty. This delineation might have important prognostic implications, and its implementation in diagnostic algorithms and future mastocytosis classifications is recommended. Refinements are also suggested for the diagnostic criteria of CM, removal of telangiectasia macularis eruptiva perstans from the current classification of CM, and removal of the adjunct solitary from the term solitary mastocytoma.

Treatment strategies in mastocytosis

Treatment recommendations for mastocytosis are based mostly on expert opinion rather than evidence obtained from controlled clinical trials. In this article, treatment options for mastocytosis are presented, with a focus on the control of mediator-related symptoms in patients with indolent disease.

A 1-year-old boy with persistent, generalized eruption. Urticaria pigmentosa

A healthy 1-year-old boy born at full term after an uncomplicated pregnancy presented to the dermatology clinic for a widespread eruption with gradual onset since 3 months of age. He was otherwise well, afebrile, feeding well, and gaining weight appropriately. The child was overall asymptomatic, though some of his lesions occasionally became red and pruritic. His mother noticed that after mild illnesses, he was more prone to these flares. She denied flushing, vomiting, diarrhea, respiratory distress, and irritability. He was meeting all developmental milestones and started walking at 11 months of age. The remainder of his review of systems was unremarkable, and family history was noncontributory. Physical exam revealed a well-appearing, well-nourished, playful, and interactive toddler. There were innumerable discrete and coalescing pink-brown macules and papules concentrated on the trunk and extending onto the proximal upper and lower extremities bilaterally, as well as the neck and lower face. Stroking the lesions quickly led to development of erythematous edematous wheals. There was no hepatosplenomegaly, and the lymph node exam was unremarkable.

Mastocytosis in children and adults: clinical disease heterogeneity

Mastocytosis is a clonal disease of the hematopoietic stem cell. The condition consists of a heterogeneous group of disorders characterized by a pathological accumulation of mast cells in tissues including the skin, bone marrow, liver, spleen and the lymph nodes. Mastocytosis is a rare disease which occurs both in children and adults. Childhood onset mastocytosis is usually cutaneous and transient while in adults the condition commonly progresses to a systemic form. The heterogeneity of clinical presentation of mastocytosis is typically related to the tissue mast cell burden, symptoms due to the release of mast cell mediators, the type of skin lesions, the patient's age at the onset and associated haematological disorders. Therefore, a multidisciplinary approach is recommended. The present article provides an overview of clinical symptoms, diagnostic criteria and treatment of mastocytosis to facilitate the diagnosis and management of mastocytosis patients in clinical practice.

[Childhood-onset mastocytosis]

Mastocytoses are a group of rare diseases characterized, in most cases, by a benign proliferation and accumulation of mast cells in different tissues. In children, mastocytosis affects usually exclusively the skin and differs in many aspects from adult-onset mastocytosis. Except for diffuse cutaneous mastocytosis, which is an uncommon subtype of childhood-onset mastocytosis, involvement of the bone marrow or additional extracutaneous organs is rarely seen in children. The prognosis of childhood-onset mastocytosis is usually very good. Compared to adult patients who most commonly experience chronic-stable or slowly progressive disease, mastocytosis in children is mostly transient and self-limiting. In this review, we present and discuss the subtypes of childhood-onset mastocytosis, recent advances in the understanding of their pathogenesis as well as similarities and differences between adult- and childhood-onset mastocytosis.

Caso clínico de urticaria pigmentosa en el adulto

Objetivo: El objetivo de esta presentación de caso es mostrar el abordaje, seguimiento, tratamiento y medidas que se tomaron para un paciente adulto con urticaria pigmentosa, la cual es una enfermedad poco frecuente en la práctica diaria y que es un reto para el diagnóstico del médico general. Resultados y Conclusiones La urticaria pigmentosa es una de las formas más comunes de las mastocitosis, las cuales corresponden a una serie de procesos caracterizados por un aumento anormal de los mastocitos en diversos órganos y tejidos corporales. En la urticaria pigmentosa la manifestación es exclusiva de la piel, caracterizada por la presencia de lesiones maculopapulares de 2.5 a 5 mm de diámetro, de un color que puede oscilar entre rojo y café, distribuyéndose generalmente en tronco y extremidades respetando palmas y plantas, cerca de la mitad de los lesiones presenta rubor localizado, prurito y ampollas. Su incidencia y prevalencia son desconocidas sin embargo su aparición es más común en niños que en adultos. El diagnostico depende en gran manera de un adecuado examen físico complementado con estudios de laboratorio e histopatología. El tratamiento de elección constituye la administración de antihistamínicos orales. [Avila J, Cala J, Rodriguez J, Torres V.Urticaria pigmentosa. MedUNAB 2012; 15(1):63-67].

Cutaneous mastocytosis associated with congenital alopecia

Mastocytosis is a rare disorder that shows accumulation of mast cells in tissues. Atypical clinical features may mimic impetigo, Langerhans cell histiocytosis, and carcinoid syndrome; however, only 1 case of scarring alopecia associated with mastocytosis has been reported. We present the first case of cutaneous mastocytosis associated with congenital alopecia areata in a 3-year-old Korean girl. This case showed an atypical clinical presentation of congenital alopecia areata, but histopathological results confirmed the diagnosis of cutaneous mastocytosis.

Diffuse cutaneous mastocytosis: analysis of 10 cases and a brief review of the literature

BACKGROUND

Diffuse cutaneous mastocytosis (DCM) is an extremely rare disease characterized by mast cell (MCs) infiltration of the entire skin. Little is known about the natural course of DCM.

OBJECTIVES

We decided to characterize clinical manifestations, the frequency of MCs mediator-related symptoms and anaphylaxis, risk of systemic mastocytosis (SM) and prognosis, based on 10 cases of DCM, the largest series published to date.

METHODS

Diffuse cutaneous mastocytosis, DCM was confirmed by histopathological examination of skin samples in all cases. SCORing Mastocytosis (SCORMA) Index was used to assess the intensity of DCM. The analysis of clinical symptoms and laboratory tests, including serum tryptase levels was performed. Bone marrow biopsy was done only in selected cases.

RESULTS

Large haemorrhagic bullous variant of DCM (five cases) and infiltrative small vesicular variant (five cases) were identified. The skin symptoms appeared in age-dependent manner; blistering predominated in infancy, whereas grain-leather appearance of the skin and pseudoxanthomatous presentation developed with time. SM was not recognized in any of the patients. Mast cell mediator-related symptoms were present in all cases. Anaphylactic shock occurred in three patients. Follow-up performed in seven cases revealed slight improvement of skin symptoms, reflected by decrease of SCORMA Index in all of them. Serum tryptase levels declined with time in six cases.

CONCLUSIONS

Diffuse cutaneous mastocytosis, DCM is a heterogeneous, severe, cutaneous disease, associated with mediator-related symptoms and risk of anaphylactic shock. Although our results suggest generally favourable prognosis, the review of the literature indicate that SM may occur. Therefore, more guarded prognosis should be given in DCM patients.

A case of mast cell leukaemia with exon 9 KIT mutation and good response to imatinib

BACKGROUND

Mastocytosis is a myeloproliferative neoplasm characterized by the excessive proliferation of mast cells. Mast cell leukaemia (MCL), the aggressive form of this disease, requires cytoreductive therapy, such as cladribine, interferon-alpha-2b and, most recently, tyrosine kinase inhibitors - dasatinib or imatinib.

PATIENT AND METHODS

We present a case of a 56-yr-old female patient with aleukaemic MCL in whom the typical KIT-D816V mutation was not detected. Sequencing of the entire coding sequence of KIT gene revealed a somatic mutation in exon 9 (p.A502_Y503dup). This mutation was previously reported in patients with gastrointestinal stromal tumours (GIST). Considering the good response to imatinib in such patients, therapy with imatinib was attempted in our patient. The treatment tolerance and outcomes were very good, with reduced mast cell infiltration of the bone marrow, normalization of the serum tryptase concentration and resolution of the clinical signs and symptoms.

CONCLUSIONS

In the absence of the KIT-D816V in systemic forms of mast cell proliferation, a search for other mutations is indicated, preferably by sequencing the entire KIT gene, as this can influence the choice of treatment. The finding of the p.A502_Y503dup in exon 9, a mutation which has been observed in GIST but not previously reported in any form of aggressive mastocytosis, can be associated with a good response to imatinib in both diseases.

Contemporary challenges in mastocytosis

Mastocytosis denotes a wide range of disorders characterized by having abnormal growth and accumulation of mast cells. Mast cells contain histamine and other inflammatory mediators, which have diverse actions within the body, and play crucial roles in acquired and innate immunity. The diverse actions of these inflammatory mediators can lead to puzzling symptoms in individuals with mastocytosis. These symptoms can include flushing, pruritus, nausea, vomiting, abdominal pain, diarrhea, vascular instability, and headache. These clinical features generally divide into cutaneous and systemic manifestations, giving rise to the two divisions of mastocytosis: cutaneous mastocytosis (CM) and systemic mastocytosis. CM has a highly favorable clinical prognosis. Systemic mastocytosis has a range of severity, with the milder forms often remaining chronic conditions, while the severe forms have rapid complex courses with poor prognoses. Generally, treatment is aimed at avoiding mast cell degranulation, inhibiting the actions of the constitutive mediators released by mast cells and, in severe cases, cytoreductive and polychemotherapeutic agents. Behavioral intervention includes avoidance of triggers, such as heat, cold, pressure, exercise, sunlight, and strong emotions. Treatment for released histamine and other inflammatory mediators includes H1 antihistamines, H2 antihistamines, proton pump inhibitors, anti-leukotriene agents, and injectible epinephrine (for possible anaphylaxis). For severe cases, treatment includes cytoreductive agents (interferon alpha, glucocorticoids, and cladribine) and polychemotherapeutic agents (daunomycin, etoposide, and 6-mercaptopurine). For very specific and severe cases, tyrosine kinase inhibitors, imatinib and midostaurine, have shown promise.

The problem of anaphylaxis and mastocytosis

Mastocytosis is a rare disease characterized by an elevated whole body mast cell number. Anaphylaxis is a severe, generalized hypersensitivity reaction with rapid onset. The problem of anaphylaxis and mastocytosis is due to strongly increased mediator release from the elevated mast cell number during allergic reactions. This explains the much higher prevalence of anaphylaxis in mastocytosis than in the general population and its severe and sometimes fatal course. Because of the increased risk of anaphylaxis in mastocytosis, all patients with severe or recurrent anaphylaxis should be analyzed for underlying mastocytosis by estimation of baseline serum tryptase. If this is elevated, patients also should be tested via skin examination for cutaneous mastocytosis and with a bone marrow biopsy. All patients with mastocytosis and anaphylaxis must be instructed about avoiding the responsible elicitors and should carry an emergency kit with adrenaline for self-application. In mastocytosis patients with anaphylaxis due to Hymenoptera stings, venom immunotherapy is recommended for life.

Anesthesia in children with mastocytosis--a case based review

INTRODUCTION

Mastocytosis is a rare heterogeneous disease of bone marrow origin which arises as a consequence of abnormal growth and/or accumulation of clonal mast cells in one or more organs. Sixty-five percent of patients with mastocytosis are children in whom it usually regresses around puberty. Adult patients with mastocytosis have been identified as at high risk of widespread mast cell degranulation in the perioperative period, this finding has not been reported in pediatric patients. This information has been repeated in mastocytosis websites where it has the potential to cause disproportionate alarm in parents.

METHODS

We considered our experience of six children with mastocytosis together with a review of the literature to examine other reports of anesthesia in children with mastocytosis. Our literature search found 57 general anesthetics in 39 children with mastocytosis. In addition, we searched for information about current consensus in diagnosis, classification and treatment of mastocytosis and in vitro and in vivo studies looking at mast cell behavior in response to drugs commonly used during anesthesia.

DISCUSSION

The literature search revealed that general anesthesia has precipitated life threatening complications in adult patients with systemic mastocytosis (SM) but no such complications have been described in children with mastocytosis. Our own experience with children with mastocytosis is of uneventful anesthesia. Advances in the understanding of the genetic basis of mastocytosis suggest that pediatric cutaneous mastocytosis (CM) and SM are different entities. SM in children is extremely rare and is associated with elevated baseline serum tryptase. There are few reports of anesthesia in this group.

CONCLUSION

The risks for most pediatric patients are overstated by mastocytosis websites. Most pediatric patients with CM do not appear to be at risk of widespread mast cell degranulation during anesthesia but because of the small number of cases reported, the risk cannot be ascertained with confidence. Children with SM and a high baseline serum tryptase (marker of mast cell burden) may merit extra precautions but experience in this subgroup is even more limited. Drugs which cause minimal histamine release can be selected from the range of drugs available in most pediatric centers without compromise to technique.

Mastocytosis in children: a protocol for management

Mastocytosis is characterized by an increased number of mast cells with an abnormal growth and accumulation in one or more organs. In most children mastocytosis is limited to the skin (cutaneous mastocytosis) and often transient as compared with that in adults in whom mastocytosis is usually progressive and systemic. Generally, we recognize three more common forms of cutaneous mastocytosis: maculopapulous mastocytosis (formerly urticaria pigmentosa), mastocytoma of skin, and diffuse cutaneous mastocytosis. Childhood mastocytosis can further be divided into cutaneous mastocytosis (nonpersisting and persisting) and systemic mastocytosis (extremely rare). An approach to management using a set protocol is described in table form. In most cases of mastocytosis, only yearly checkups are necessary and no treatment is required; preventive recommendations are warranted in those individuals with systemic disease and constitutional symptoms. Symptomatic therapy is advised in only a minority of cases. This article is meant as a guideline for physicians involved in the care of children with mastocytosis and their parents.

Phenotypic and genotypic characteristics of mastocytosis according to the age of onset

Adult's mastocytosis is usually associated with persistent systemic involvement and c-kit 816 mutation, while pediatrics disease is mostly limited to the skin and often resolves spontaneously. We prospectively included 142 adult patients with histologically proven mastocytosis. We compared phenotypic and genotypic features of adults patients whose disease started during childhood (Group 1, n = 28) with those of patients whose disease started at adult's age (Group 2, n = 114). Genotypic analysis was performed on skin biopsy by sequencing of c-kit exons 17 and 8 to 13. According to WHO classification, the percentage of systemic disease was similar (75 vs. 73%) in 2 groups. C-kit 816 mutation was found in 42% and 77% of patients in groups 1 and 2, respectively (p<0.001). 816 c-kit mutation was associated with systemic mastocytosis in group 2 (87% of patients with systemic mastocytosis vs. 45% with cutaneous mastocytosis, p = 0.0001). Other c-kit activating mutations were found in 23% of patients with mastocytosis' onset before the age of 5, 0% between 6 and 15 years and 2% at adults' age (p<0.001). In conclusion, pathogenesis of mastocytosis significantly differs according to the age of disease's onset. Our data may have major therapeutic relevance when considering c-kit-targeted therapy.

Tryptase detection in bone-marrow blood: a new diagnostic tool in systemic mastocytosis

BACKGROUND

The condition mastocytosis includes a heterogenous group of disorders that are characterized by abnormal growth and accumulation of mast cells. The detection of serum tryptase, an essential mast cell enzyme, is a widely used tool in the diagnosis of mastocytosis. The diagnosis of systemic mastocytosis is substantially based on the histologic examination of bone-marrow biopsy specimens.

OBJECTIVE

We hypothesized that the detection of tryptase in bone-marrow blood might provide additional, more sensitive information on the bone-marrow involvement of patients with mastocytosis.

METHODS

Serum tryptase was monitored in patients with cutaneous symptoms (n = 17), patients with extracutaneous symptoms (n = 16), and healthy control subjects (n = 359). Bone-marrow biopsy specimens of patients with systemic mastocytosis (n = 7) and control subjects (n = 7) were investigated histologically and bone-marrow blood of these individuals was analyzed on the tryptase levels.

RESULTS

We could detect for the first time significantly elevated tryptase levels in bone-marrow blood of patients with systemic mastocytosis. Secondarily we could present a clear correlation between the level of serum tryptase and the clinical symptoms of mastocytosis.

LIMITATIONS

With the present study, we establish a new diagnostic tool for systemic mastocytosis. Unfortunately, we can only present a limited number of cases, since systemic mastocytosis is a rare disease involving few patients.

CONCLUSION

Our results indicate that the measurement of tryptase in bone-marrow blood is a new, sensitive marker of the mast cell burden in bone marrow of patients with systemic mastocytosis.

Midline cutaneous lumbosacral lesions: not always a sign of occult spinal dysraphism

OBJECTIVE

The authors report two unusual cases of extraspinal midline lumbosacral lesions that resembled the usual skin markers of occult spina bifida.

PATIENTS AND METHODS

The pathological diagnosis of the masses was plexiform neurofibroma and mastocytoma, respectively.

RESULTS

Some lesions, as those we are reporting, although occurring at the lumbosacral midline, do not necessarily belong to occult spinal dysraphism, as was initially suspected. Plexiform neurofibroma and skin mastocytoma are very rare indeed in this spinal location.

CONCLUSION

The two cases represent an important addition to the differential diagnosis of a congenital dorsal midline mass.

Neonatal mastocytosis with pachydermic bullous skin without c-Kit 816 mutation

BACKGROUND

Bullous mastocytosis is an unusual variant of mast cell disease with widespread bullae as the main cutaneous feature induced by mast cell proteases that cause dermoepidermal separation.

CASE REPORT

A rare case of diffuse cutaneous bullous mastocytosis with pachydermia and unusually extensive skin folding is described in a 3-week-old girl. The diagnosis was confirmed by immunohistochemistry with Giemsa stain, the naphthol ASD chloroacetate esterase reaction and elevated blood levels for tryptase, histamine in serum and histamine and 1.4-methylimidazol acetic acid in the 24-hour urine. Blood cell count was normal, as were thrombocytosis and leukocytosis. FACS analysis of the bone marrow aspiration material showed 1% mast cells. No c-Kit 816 [Asp-->Val] somatic mutation was found. Systemic involvement of other organs was excluded.

DISCUSSION

The prognosis of c-Kit-negative diffuse bullous mastocytosis is not known. Regular blood controls are mandatory, and screening for germ cell ovarian cancer and bone marrow controls should be performed as well.

Mastocitose bolhosa na criança: relato de caso

A mastocitose é doença rara, definida como a infiltração desordenada de mastócitos em vários tecidos. Compreende diferentes quadros clínicos, variando de formas cutâneas indolentes a condições sistêmicas e malignas. O termo mastocitose bolhosa descreve a variedade na qual a lesão cutânea bolhosa é o aspecto predominante e geralmente indica casos de mastocitose cutânea. É mais comum na criança e possui prognóstico mais reservado. Este relato de caso enfatiza a diversidade de suas manifestações clínicas e as complicações decorrentes.

Urticaria pigmentosa

Urticaria pigmentosa (UP), resulting from the accumulation of excessive numbers of mast cells in the skin, is the most common form of cutaneous mastocytosis. Observations highlight the diversity of this disease. Clonal expansion of early hematopoietic progenitor cells carrying activating mutations in KIT seems to be the basis of adult-onset UP. New pathogenetic findings are leading to the development of new diagnostic surrogate markers of disease and therapeutic approaches targeting neoplastic mast cells. Promising strategies may arise from an increased understanding about the cause of mastocytosis and the signaling pathways initiated by kit activation.

Mastocytose systémique du nourrisson : à propos d’un cas avec atteinte respiratoire et digestive

Systemic mastocytosis is rare in children and is characterized by an abnormal proliferation and infiltration of mast cells in different tissues.

CASE REPORT

We report a case of systemic mastocytosis presenting cutaneous symptoms during the neonatal period. Later evolution was characterized by systemic manifestations consisting of recurrent respiratory infections with wheezing and a digestive involvement that included abdominal pain, hepatosplenomegaly and a nodular, hemorrhagic infiltrate in a low esophagus. The diagnosis was confirmed by histology and biology, notably increased histamine concentrations in blood and urines. Improvement of the respiratory and digestive symptoms was obtained with treatment by histamine H1 and H2 receptors antagonists.

CONCLUSION

Respiratory manifestations and nodular infiltration of the digestive tract are rare in systemic mastocytosis. The prognosis is conditioned by complications such as malignancy and the persistence of the disease till the adult age.

[Pediatric dermatotherapy]

Dermatological therapy of children differs considerably from treatment of adults and poses a special challenge. Dermatological diseases often form idiosyncratic entities with a prognosis different from adults and must be treated appropriately. Consideration should also be given to the fact that children occasionally experience adverse reactions to drugs, which are not observed in adults. A selection of dermatological diseases and typical drug reactions are presented to illustrate the special features and differences between pediatric dermatotherapy and treatment of adults.